I just tweaked my documents on a transformational approach to triangle congruence and similarity, thanks to feedback from Bill McCallum.
– Version 1 (more opinionated and footnoted)
– Version 2 (co-authored with Lew Douglas, better section on similarity)
The main change is to the SAS proof, which did not correspond to its illustration. If you downloaded earlier versions, please delete them and replace them with the current versions.